Internal-combustion-motor cylinder



J. E. DIAMOND. INTERNAL COMBUSTION MOTOR CYLINDER. APPLICAHDN FILED 001. N. I916.

1 347,478 Patented J uly 20, 1920.

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UNITED STATES PATENT OFFICE.

JAMES E. DIAMOND, OF CLEVELAND, OHIO, ASSIGNOR TO THE ALUMINUM CASTINGS COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

INTERNALCOMBUSTION-MOTOR CYLINDER.

Specification of Letters Patent.

Patented July 20, 1920.

Application filed October 17 1916. Serial No. 126,1 82.

T 0 all whom it may concern:

Be it known that I, James E. DIAMOND, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Internal-Combustion-Motor Cylinders, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to improvements in the construction of the cylinders of internal combustion motors.

The object of the invention is to provide a composite cylinder of light weight, great durability and high thermodynamic and mechanical eflicienc To reduce the weight of internal combustion motors it has been proposed to cast the cylinders of metal of low specific gravity, such as aluminum alloys, each cylinder being bored out to receive a lining sleeve of iron or steel to take the wear of the piston which, also, has usually been made of aluminum alloy. Motors of this character have, in many respects, given good results. However, by reason of the high thermal conductivity of the aluminum alloys forming the cylinder casting and piston, there is a tendency for an excessive amount of the heat of combustion to go to the jacket water so that the engine runs too cool to secure as high thermodynamic efficiency as is desirable. Furthermore, while the use of the lining sleeve has tended to diminish irregularities of expansion and contraction of the piston engaging parts of the cylinder wall due to the necessary irregularities in the form of the cylinder casting. nevertheless the close contact between the lining sleeve and cylinder casting has eased the former to expand more or less irregularly with the latter, this effect being most noticeable in the hotter part of the cylinder surrounded by the water jacket. This distortion of the lining sleeve due to its irregular expansion has given rise to undue friction between the sleeve and piston and a consequent lowering of the mechanical eliiciency of the motor, and has also caused scoring of the lining and piston.

In accordance with my present invention I provide a cylinder casting of aluminum alloy or the like fitted with iron or steel lining sleeves, thus securing the advantages of light weight and durability of the earlier motors of composite construction, but in my construction, unlike the earlier ones referred to, the lining sleeves and the bores of the cylinder casting are formed to provide between them an unbroken insulating space .filled, preferably, with air and extending between the sleeve and the adjacent wall 0 the cylinder casting throughout the major part of the piston travel and especially throughout the upper, hotter part of the ilrylinder surrounded by the water jacket.

ythis means I avoid excessive heat losses and secure a higher working temperature and also secure a highly uniform expansion ofzthe lining sleeves, so that the distortion and consequent friction marking prior constructions are avoided.

In order that my invention may be clearly understood 1 will now describe a preferred form of construction, referring therein to the accompanying drawing.

In the drawing- Figure 1 is a transverse vertical section of one of the cylinders of an engine embodying my improvements.

Fig. 2 is a detached perspective view of a cylinder lining sleeve.

Referring in detail to the construction illustrated in the drawing. 1 designates the cylinder casting in its entirety, said casting comprising the cylinder wall 1, the water jacket 1, suitable intake and exhaust valvepassages (not shown in full lines), and the upper crank case section l. The cylinder casting is formed of alloy metal of low specific gravity, preferably aluminum alloy of suitable composition for the purpose.

The cylinder casting has its main cylindrical chamber bored out, preferably with a continuous cylindrical inner surface, to receive a piston wear-resisting sleeve 2 which is prefeably made of iron or steel. This lining sleeve is preferably machined inside and out, being of uniform thickness throughout except at its uppen and lower ends. At the upper end the sleeve is formed with an out-turned flange \vhiclr'tits in a corresponding countersinlflin the upper end of the casting. and below said flange with an integral collar or enlargement 2 which fits the bore of the sleeve casting and series to center the upper end of thisleeve therein. its lower end the sleeve 2 is formed with an outward enlargement or collar '3". which fits the bore of the cylinder casting and serves to center the lower end of the sleeve therein. By reason of this formation of the lining sleeve an insulating air space 3 is formed between the sleeve and the adjacent inner wall of the cylinder casting, this air space extending unbroken from the collar 2 at the upper end of the sleeve to the collar 2 at the lower end thereof by machining the interior of the cylinder casting with an accurate cylindrical surface and relieving the outer wall of the sleeve when it is machined, the thickness of the insulating space between the cylinder casting and the sleeve can he nicely determined.

The upper end of the cylinder is closed by a head casting designated as an entirety by 4, this casting having a water jacket 4. communicatin in the usual and well known manner with the watcr jacket 1 of the cylinder casting. The combustion space 5 formed in the head casting has an extension 5* which communicates with the inlet and exhaust passages through valve controlled openings in the usual manner; in the drawing the exhaust valve is shown at 6 and it will be understood that the inlet valve is in that part of the structure which does not ap war.

he sleeve 2 may be secured in the cylinder in any desired manner but is preferably clamped in place by the head casting l which, of course, is securely attached to the cylinder casting 1.

7 designates a piston arranged to reciprocate in the cylinder in the usual manner, being connected by connecting rod 8 with the crank 9 of the engine shaft 10. The piston may be of any suitable form of construction but, in an engine of this character, is preferably made of light weight alloy metal such as is used for the cylinder casting.

1nthe operation of my improved engine, as the piston moves downward on its working stroke, the upper part of the lining sleeve 2 is uncovered and subjected to the high temperature of the burning gases; but, because of the interposed insulatin space the sleeve 2 is unable to conduct its a sorbed heat directly to the metal of the jacket wall of the cylinder casting and thence to the water in said jacket. Of course, a small amount of heat will pass through the insulating space, in case air constitutes the insulating medium, but only a relatively small amhunt. Also some heat is conducted to the. cylindcr casting at the upper and lower ends of the lining sleeve; but the area of contact of the sleeve and cylinder casting at the upper end of the sleeve is small, and the major part of any heat that goes to the cylinder casting at the lower end of the sleeve must be conducted downward through the relatively small cross-sectional area of the sleeve. Obviously, therefore, the amount of heat conducted to the cylinder cast ng in this way is very much less than would be cot ducted b a lining sleeve fully in contact with salt casting.

Thus it will be seen that the high thermal conductivity of the aluminum alloy 0 linder casting is oll'set by the insulation 0 the lining sleeve from the cylinder casting, the dissipation of heat to the jacket water is checked and the lining sleeve 2 and consequently also the piston Tare maintained at a temperature sufiicicntly high to realize the highest possible thermodynamic efficiency in the operation of thc cnginc that is consistent with proper lubrication.

here. as in the preferred construction described. a piston of aluminum alloy is employed. the latter. by reason of its high thermal condmztivity, tends to rapidly absorb the heat of combustion and to conduct it to the cylinder lining so that usually it is advisable to carry the insulating space between the lining sleeve and the cylinder casting well below the water jacket.

As has been pointed out, the liner 2 is of uniform thickness throughout the length of the insulating space 3, and. inasmuch as it is out of contact with the cylinder casting throughout said length, a practically perfect uniformity of expansion and contraction is secured. the heat being uniformly distributed through thc metal of the liner. while said metal is free to expand and contract without constraint from the walls of the cylinder casting which, as has been pointed out. are necessarily irregular in form and dillicult to maintain at a uniform temperature throughout.

The construction herein set forth is for purposes of illustration and explanation and in no sense intended as a limitation of my invention. Those skilled in the art will understand that various changes in the forms and proportions of the parts may be made in carrying out my invention and, in

particular, it should be understood that thedimensions of the heat insulating space are to be determined. preferably by ei perimental tests. in accordance with the-"Esquirements in each particular design of motor.

What I claim is:

1. A composite internal combustion motor c linder comprising a casting of metallic alloy having a high coefficient of heat conductivity and fgtifified with an inner cylindrical wall surrounded by a water jacket, and a wear-resisting lining sleeve operatively secured within the said cylindrical wall with a continuous heat insulatin space extending between the water jackete part of the said cylindrical wall and the sleeve.

2. A composite internal combustion motor cylinder comprising av casting of metallic alloy having a high coefficient of heat conductivity and formed with an inner cylindrical wall surrounded by a water jacket, and a wear-rcsistin; lining sleeve operatively secured within the said cylindrical wall, the adjacent surfaces of the cylinder wall and sleeve being formed to afford close contact between the two parts at the ends of the sleeve and to provide a heat insulating space between the two parts extending continuously between the regions of contact at the ends of the sleeve.

3. A composite internal combustion motor cylinder comprisin; a casting of metallic alloy having a high coefficient of heat conductivity and formed with an inner cylindrical wall surrounded by a water jacket, and a weara-esistinc lining sleeve operatively secured within the said cylindrical walL the said cylindrical wall being formed with a continuous smooth cylindrical inner surface and the adjacent outer surface of the said sleeve being formed to afford close contact between the two parts at the ends of the sleeve and to provide a heat insulating space between the two parts extending continuously between the regions of contact at the ends of the sleeve.

JAMES E. DIAMOND.

Correction in Letters Patent No. 1,347,478.

It is hereby certified that in Letters Patent No. 1,347,478, granted July 20, 192g),

) upon the application of James E. Diamond, of Cleveland, Ohio for an improvel ment in Internal-Combustion-Motor Cylinders," an error appears in the printed specification requiring correction as follows: Page 2, line 8, after the word thereofi insert a period and capitalize the b of the word "by"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 17th day of August, A. D., 1920.

M. H. COULSTON, Acting Commissioner of Patents.

[SEAL] 

